The aim of this unit is to test whether the internal diameter of the tested sample is within standard or not. Judgment of reference: the small end must adapt to the internal circle of the samples, while the larger end should not adapt to the internal circle of the samples. It can be custom-made as different diameters.

The aim of this unit is to test whether the outside diameter of the tested sample is within standard or not. Judgment of reference: the samples must adapt to the larger hole, while the samples must not adapt to the small hole.

Used for testing the air-tightness of the crown cap. Stainless steel design ensures the durability of the tester during test. Cap the crown cap on the neck of the bottle mold, plunge the cap in the water tank, then increase the internal pressure and observe if there are air bubbles coming out, so that to test the air tightness of the caps.